Ex post Evaluation of the Impact of the Environmental Mitigation Measures for the Porce II Hydroelectric Power Plant Project

This evaluation helps to address the need in literature on Environmental Impact Assessment during the monitoring of operations and ex post evaluations. It helps to develop innovative methodologies for ex post environmental assessments for both the IDB and borrowers. The evaluation uses environmental monitoring data for infrastructure projects through an analysis of indicators and their long-term trends. In general, the evaluation results indicate that the Porce II Hydroelectric project's mitigation measures were relevant for four of the environmental aspects considered, with the exception of landscape. The proposed mitigation measures were effective, on the assumption that the environmental quality of the surrounding area would have deteriorated had the project been executed without any mitigation measures. The capacity to implement and keep environmental management measures up to date is considered sustainable thanks to the institutionalization of environmental matters and technical capacity-building by the organization. The IDB also added value to the design of some environmental aspects by requiring specific studies, such as watershed management, water quality and the epidemiological surveillance system.